Original title: Summary of detailed steps for the popularization of
down-the-hole drilling tools and daily preservation
Size selection of down-the-hole impactor, drill bit and drill pipe
The size of the down-the-hole impactor mainly depends on the hole diameter and the type of rock.For blast holes, the diameter range of the down-the-hole drilling is from 89mm To 252mm, Less than 89mm The aperture is mainly the top hammer type, which is larger than 252mm Multi-purpose rotary drilling method of hole diameter.
Generally speaking, DTH impactor can be applied The smallest aperture is its nominal size,it means The smallest aperture for an inch impactor is4Inch aperture.Generally speaking, in this case, between the impactor and the hole wall, between the drill pipe and the hole wall, there is enough annular space for slag discharge.
The maximum size of the matching drill bit is the size of the impactor plus 1 Inch, For example, matches The maximum bit size of an inch impactor is 5 Inch.
The closer the outer diameter of the drill pipe to the outer diameter of the impactor, the better, Can ensure better slag discharge, but also reduce the possibility of stuck drill.
From the processing technology of drill pipe (drill pipe),The surface finish and dimensional accuracy of cold drawn tubes are better than hot rolled tubes.Good surface finish means that the surface of the steel pipe is not easy to peel, and the metal chips caused by the peeling will reduce the service life of the impactor.In addition, if the thread of the drill pipe and the connection part of the main body are usedFriction welding Even better, it can increase the strength of the drill pipe. At the same time, the heat treatment of the threaded part is done well, which can increase the reliability and strength of the thread, make the connecting and unloading rods smoother, and improve the work efficiency and the overall piercing speed..
Choosing the right
down-the-hole drill bit
Let's take a look at the drill bit. The body of the drill bit is usually machined by cemented carbide, and then heat treated to the specified hardness, so that the compressive stress on the surface has sufficient fatigue resistance, and then the cemented carbide drill teeth are inserted..
The convex and pointed bit design can achieve the fastest perforation efficiency, and is most suitable for medium and soft rocks with low grindability..
For grindstone SD50 DTH Hammer Hard rock, flat drill bit can increase the life of the drill bit.If the outer edge of the button is large enough, you can improve the life of the drill by grinding the drill several times and reduce the cost of use.In addition, the concave button bit can also be applied to this kind of hard rock with high grindability..
As shown below,Concave drill bits are more suitable for medium-hard rocks with well-developed joints and many fissures, Can effectively reduce the probability of hole deflection, which was also mentioned in the previous article series.
Practical application
Drilling in open-pit mines and quarries usually requires a more durable down-the-hole impactor, because the quarry is usually a long-term work, if the impactor is frequently replaced, it is too cost-effective.Some good down-the-hole impactors can be repaired and used many times before being completely replaced, such as changing the direction of the outer tube of the impactor..
Drilling of building stone (marble, etc.) pays more attention to the straightness of the hole.89mmIn borehole drilling, the down-the-hole type is usually better than the top hammer type..
Exploration drilling needs to work on relatively remote sites with poor related facilities.Therefore, the requirements for the down-the-hole impactor are simple design, high reliability, and adapt to high wind pressure drilling..
Reverse circulation percussion drilling is also commonly used. This sampling method is relatively cost-saving for diamond core drilling..The reverse circulation impactor uses the same process as the ordinary down-the-hole impactor, but uses a reverse circulation drill pipe. High-pressure air is blown in through the gap between the inner and outer walls of the drill pipe, and then the drill cuttings are discharged from the inner wall of the drill pipe , And then use a dust bag to collect drill cuttings, as shown in the figure below.
In actual use, an important factor must always be considered, that is, the rig.An experienced driller can effectively adjust the drilling parameters to reduce the probability of failure of the impactor and increase the life of the impactor.
There are many choices of impactors on the market, some are cheap and some are high-end.But to measure the value of the impactor is not only to look at the material and design itself, but also to consider the balance between the efficiency brought to the user and the cost of Iwami..
For example, an impactor is cheap and durable, but its fuel consumption is high. As a result, the cost of rock rice is very high. This cannot be said to be a good impactor..The price of another impactor is very high, but the efficiency is also high, and the cost per rock meter is low, so this is a good impactor.
Of course, as a user, you also need to consider whether the impactor manufacturer can provide sufficient technical support and instructions for use. This is also very important, which can effectively help our users improve drilling efficiency and reduce operating costs..
Preservation of drill pipe
First, blow the air to remove the water inside the drill pipe, and open the shank lubrication device at the same time. In principle, it is better to see the shank lubricating oil at the bottom of the drill pipe..
Second, the outside of the drill pipe, including the threaded part and the main part of the drill pipe, must be wiped clean.At the same time, a rubber cover should be added to the male and female joints (as shown below) to prevent pollutants from entering.
Saving and reactivation of the impactor
Short-term preservation, Follow the steps below:
First, blow the air to remove the moisture in the impactor;
Second, add 1 liter of shank oil from the upper joint part;
Third, turn on the wind and blow for about 10 seconds, so that the internal parts of the impactor can be fully lubricated;
Fourth, just like the drill pipe, cover the upper joint and the lower joint with rubber caps;
Fifth, place the impactor horizontally in a dry environment.
Long-term preservation, Slightly different
the first,Air blow to remove the moisture in the impactor;
Second, loosen the upper joint and the lower joint, and disassemble the impactor;
Third, check and wipe all internal parts, preferably in a clean room;
Fourth, use suitable lubricating oil to moderately lubricate all parts;
Fifth, assemble the impactor and cover the upper and lower joints with rubber caps;
sixth,Place the impactor horizontally in a dry environment.
Re-enableThe impactor requires the following three steps
First, disassemble the impactor, inspect all internal parts,If you find that the surface of some parts is oxidized, you need to sand the oxidized part with sandpaper..
If it is directly put into use without testing, it is likely to cause premature failure of the impactor.
second,Clean each part, wipe it clean, and lubricate it,
Third, assemble the cleaned and lubricated parts into an impactor, which can then be put into use.
After reading the above article, many people may think that we usually put it casually, but we still use it.?!
Many users will record the wear and tear of
drilling tools, such as an impactor used for several months, etc..In today's sluggish market and fierce competition, the price of Iwami drilling is declining. The editor advises our users of down-the-hole drilling rigs to try to work hard on maintenance, such as using and storing drilling tools in accordance with our recommended methods. Carry out reasonable maintenance and lubrication according to the requirements, and try to see if the life of the drilling tool can be longer than before, which will help you save more money.
Machines are more reliable than humans,If you treat the machine well, the machine will treat you well
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